One purpose of optic piece (e.g., lens) edge-machining is to finish an edge of the piece. For example, a spectacle lens is typically finished in such a way that the lens may be inserted into a spectacle frame. Various arrangements or systems are known which serve to mount the lens for edge-machining and to clamp or otherwise secure it between rotatable holding shafts of a lens edge-machining machine. As used herein, spectacle lenses can mean optical lenses or lens blanks for spectacles made of the usual materials, such as polycarbonate, inorganic glass, CR-39, HI-Index etc., and with circumferential edges of any shape, which lenses or lens blanks may be, but do not have to be, machined on one or both optically effective surfaces prior to machining of the edge thereof.
Lens edge finishing systems can comprise, among other structures, a securing structure (also frequently termed a “block” or “blocking member”), which may be attached detachably to one side of the lens; an adapter for the securing or blocking structure, which may be connected rigidly to one of the holding shafts of the lens edge-machining machine and can be constructed for rotation angle-oriented rotary drive of the securing or blocking structure; and a clamping assembly, which can comprise a fastening portion, connectable rigidly to the other holding shaft of the lens edge-machining machine, and a clamping portion which can be connected to the fastening portion, and which clamping portion can be constructed for force-locking engagement with the other side of the lens. The securing structure can be attached to the optical lens by means of an adhesive film portion or pad which can include adhesive on both sides.
To date, securing structures have suffered from or been susceptible to various drawbacks. For instance, an amount of air may enter between the lens being finished or machined, which can result in reduced bonding or adhesion between the lens and the securing structure. Reduced bonding, in turn, can tend to result in some amount of shifting and/or rotation of the lens (e.g., relative to the securing structure or overall finishing assembly) during a machining operation.
It would be desirable to provide a new securing structure that overcomes the aforementioned and other drawbacks. Further, it would be desirable to provide a new securing structure that can be manufactured in a cost-effective manner.